1. Field of the Invention
The present invention relates to an integrated circuit (IC) testing interface, and more particularly, to an IC testing interface capable of upgrading an automatic test equipment (ATE) for testing a semiconductor device.
2. Description of the Prior Art
Since the Liquid Crystal Display (LCD) price is going lower and the quality is improving, the LCD has been broadly used in IT products such as personal computers, notebooks, personal digital assistants (PDAs), mobile phones, televisions, and watches.
The LCD primarily includes one or more source drivers (column drivers), one or more gate drivers (row drivers), and a panel, wherein the characteristic response between input voltage and transmittance-voltage of the liquid crystal is nonlinear. FIG. 1 shows the conventional output voltage characteristic of an LCD. In the conventional application of LCD, the internal reference voltages VL0-VL6, VH0-VH6, having positive and negative polarities in a decreasing order (or in an increasing order from negative to positive polarity), are corresponding to the output voltage curve (gamma curve) generated from the input data. Therefore, the gamma correction in the digital to analog conversion circuit is required to compensate the nonlinear characteristic.
Since the source drivers are required to receive a plurality of external reference voltages to convert the input digital signals to corresponding analog signals and output the correct voltage to data line so as to drive the pixels of the LCD panel for display, the primary function of an LCD driver IC is a digital to analog conversion. Therefore, the conventional techniques utilize the digitizer of a tester or a test board to test the LCD IC.
The industry has always been chasing after better performance of the integrated circuits and faster testing speed. In the era with booming electronic industry, the technology of integrated circuits is improving day by day. To comply with the high frequency circuit demand as well as the high complexity architecture, the life-cycle for automatic test equipment is going shorter than before, e.g. 5 years. The function specifications of legacy ATE, such as Teradyne J750, SC312, Yokogawa TS6700, merely comply with the LCD driver IC of monochrome LCD rather than colored LCD. Therefore, those old test equipments are mostly phased out.
With the price of IC chip going down, the cost of integrated circuit test should be minimized as well. The primary cost of integrated circuit test comes from consumption and upgrade of Automatic Test Equipments (ATE). However, if the life-cycle of the automatic testing equipment is about or even less than 5 years, the cost of the integrated circuit test is not possible to be reduced.
Therefore, how to develop low-cost automatic testing equipment for reducing the IC price is a topic to be addressed and discussed.